1. Field of the Invention
This invention pertains to the area of driving aids for motor vehicles. More specifically it pertains to a device which is intended to facilitate perception of driving assistance data or navigational assistance for the driver of a vehicle without the driver having to turn his attention away from the road.
2. Discussion of the Background
Numerous data display devices for vehicular highway drivers have already been proposed. For example, one can refer to the documents U.S. Pat. No. 4,729,634, EP-A-0,420,228 and EP-A-0,450,553.
The document U.S. Pat. No. 4,729,634 is concerned principally with enlarging the instantaneous field of vision of the image and projecting the virtual image of the latter to infinity.
The document EP-A-0,420,228 discloses a display device in which the windshield has two external sides which are not parallel in order to cause generation of spurious images.
The document EP-A-0,450,553 discloses a display device which includes a mirror-based optical device in which a mirror is movable as a function of the vehicle speed in order to modify enlargement of the virtual image of the imager and the position of this virtual image as a function of vehicle speed.
However, the known devices do not allow the driver to maintain a complete view of the road scene in all cases when he is consulting the display data.